Synonym for $stdout.
Alias for CSV::read()
.
Rewinds the underlying IO
object and resets CSV’s lineno() counter.
Returns a simplified description of the key CSV
attributes in an ASCII compatible String.
Returns the IO
used as stdout. Defaults to STDOUT
Sets the IO
used as stdout. Defaults to STDOUT
Taint both the object returned by _getobj_ and self.
Untaint both the object returned by _getobj_ and self.
Explicitly terminate option processing.
Returns true if option processing has terminated, false otherwise.
Returns true if the given ipaddr is in the range.
e.g.:
require 'ipaddr' net1 = IPAddr.new("192.168.2.0/24") net2 = IPAddr.new("192.168.2.100") net3 = IPAddr.new("192.168.3.0") p net1.include?(net2) #=> true p net1.include?(net3) #=> false
Returns a string containing a human-readable representation of the ipaddr. (“#<IPAddr: family:address/mask>”)
Returns true
iff the current severity level allows for the printing of INFO
messages.
Log an INFO
message.
message
The message to log; does not need to be a String.
progname
In the block form, this is the progname
to use in the log message. The default can be set with progname=
.
block
Evaluates to the message to log. This is not evaluated unless the logger’s level is sufficient to log the message. This allows you to create potentially expensive logging messages that are only called when the logger is configured to show them.
logger.info("MainApp") { "Received connection from #{ip}" } # ... logger.info "Waiting for input from user" # ... logger.info { "User typed #{input}" }
You’ll probably stick to the second form above, unless you want to provide a program name (which you can do with progname=
as well).
See add
.
Create a matrix by stacking matrices vertically
x = Matrix[[1, 2], [3, 4]] y = Matrix[[5, 6], [7, 8]] Matrix.vstack(x, y) # => Matrix[[1, 2], [3, 4], [5, 6], [7, 8]]
Create a matrix by stacking matrices horizontally
x = Matrix[[1, 2], [3, 4]] y = Matrix[[5, 6], [7, 8]] Matrix.hstack(x, y) # => Matrix[[1, 2, 5, 6], [3, 4, 7, 8]]
The index method is specialized to return the index as [row, column] It also accepts an optional selector
argument, see each
for details.
Matrix[ [1,2], [3,4] ].index(&:even?) # => [0, 1] Matrix[ [1,1], [1,1] ].index(1, :strict_lower) # => [1, 0]
Returns a section of the matrix. The parameters are either:
start_row, nrows, start_col, ncols; OR
row_range, col_range
Matrix.diagonal(9, 5, -3).minor(0..1, 0..2) => 9 0 0 0 5 0
Like Array#[]
, negative indices count backward from the end of the row or column (-1 is the last element). Returns nil if the starting row or column is greater than row_count
or column_count
respectively.
Returns the determinant of the matrix.
Beware that using Float
values can yield erroneous results because of their lack of precision. Consider using exact types like Rational
or BigDecimal
instead.
Matrix[[7,6], [3,9]].determinant => 45
deprecated; use Matrix#determinant